Energy extraction by an oscillating system from a shaker or a wave field

The purpose of our work is to study an oscillating system and an electro-dynamical transducer, which are driven either by the amplifier or wave field. In the first case electrical current produced by an amplifier is converted by the transducer into mechanical force, which leads to vibrations of the base. A mechanical oscillator is mounted on the transducer base. The influence of oscillator vibrations on the formation of the driving force leads to a number of specific effects, in particular, to the Sommerfeld-Kononenko's effect. Steady-state regimes of the constructed model are investigated by methods of the theory of dynamical systems. Expressions for supplied and consumed powers are shown and investigated for regular and chaotic regimes. The inverse problem model is also discussed. The classical results for wave power absorption by wave energy extractor as a single degree of freedom system are presented in the second considered problem. The example includes an axisymmetric buoy which oscillates and is subjected to its natural hydrostatic restoring force. Main attention focuses on the values and expressions for the mean powers. The expression for the maximum mean power is given for the considering system.